A high profile lawsuit is under way in the UK against a radio audience measurement body over its refusal to change its monitoring methods.

The Wireless Group, headed by former tabloid newspaper editor Kelvin MacKenzie, claims RAJAR (Radio Joint Audience Research) abused its position and breached competition law by failing to introduce electronic meters in place of its favoured paper diary system.

Lawyers for both sides in London's High Court have been engaged in legal arguments over whether RAJAR has a case to answer.

RAJAR says its decision, in June last year, was justified because the meters which had been tested were not up to standard and it was waiting for newer and more accurate devices to be developed.

However, The Wireless Group says the diary system does not give a true picture of audience numbers to the detriment of its advertising revenues. The hearing continues.

Data sourced from Telegraph.co.uk; additional content by WARC staff